1. Working with Digital Video in the Classroom Jim Demmers Georgia Tech Research Institute

2. Digital Video So what is digital video? It can be a variety of things: It can be a variety of things: A movie on DVD A movie on DVD A home video stored on tape A home video stored on tape A QuickTime movie trailer on the Web A QuickTime movie trailer on the Web Digital video is stored as a series of ones and zeros Digital video is stored as a series of ones and zeros How is it different from analog video? Capture digital video - digitize analog video Capture digital video - digitize analog video Capturing is akin to copying a computer file - each generation is virtually identical to the parent Capturing is akin to copying a computer file - each generation is virtually identical to the parent Digitizing samples a fluctuating voltage signal at discreet intervals, which adds generation loss Digitizing samples a fluctuating voltage signal at discreet intervals, which adds generation loss As long as the video stays digital it doesn’t lose any integrity As long as the video stays digital it doesn’t lose any integrity

3. Video Capture Some things you need to know: Types of video signals Types of video signals Composite, S-Video, Component YUV and RGB, FireWire Composite, S-Video, Component YUV and RGB, FireWire Start with the best video source available Start with the best video source available VHS - 8mm - Hi-8/S-VHS - Beta SP/MII - DV/DVCPRO VHS - 8mm - Hi-8/S-VHS - Beta SP/MII - DV/DVCPRO Avoid generation loss Avoid generation loss Keep your frames clean Keep your frames clean Be aware of Gamma differences Be aware of Gamma differences Purchase a fast A/V hard drive Purchase a fast A/V hard drive Keep your capture drive defragmented Keep your capture drive defragmented

4. Video Capture Hard disk storage for video Ultra ATA vs Ultra2 SCSI drives Ultra ATA vs Ultra2 SCSI drives ATA is fast and cheap now ATA is fast and cheap now Drive specifications Drive specifications sustained transfer speed at least 8 MB/sec sustained transfer speed at least 8 MB/sec seek time less than 9 ms seek time less than 9 ms spindle speed at least 5400 rpm spindle speed at least 5400 rpm How much space do you need for Digital video? How much space do you need for Digital video? Data transfer rate for DV-format video is 3.6 MB/sec Data transfer rate for DV-format video is 3.6 MB/sec 3.6MB/sec * 60 sec = 216 MB/min = 13 GB/hour 3.6MB/sec * 60 sec = 216 MB/min = 13 GB/hour Multiply by 5 (for project, render & test files) = 1 GB/min Multiply by 5 (for project, render & test files) = 1 GB/min

5. Video Capture Digitizing analog video requires an A/D converter or capture card Good choices in A/D converters are: Good choices in A/D converters are: Sony DVMC-DA2 Sony DVMC-DA2 Dazzle Multimedia’s DV-Bridge Dazzle Multimedia’s DV-Bridge Formac Studio Formac Studio Power R Director’s Cut Power R Director’s Cut Good choices in capture cards for the PC are: Good choices in capture cards for the PC are: Pinnacle Studio DV Pinnacle Studio DV Canopus DV Raptor Canopus DV Raptor

6. Post Production Linear vs non-linear editing Linear editing copies shots from one video storage media to another in sequenceLinear editing copies shots from one video storage media to another in sequence Non-linear editing uses a computer hard drive as random- access storage mediaNon-linear editing uses a computer hard drive as random- access storage media Most non-linear editors are also non-destructive you can change or delete captured clips without affecting the original source clipyou can change or delete captured clips without affecting the original source clip Non-linear editing Tools Premiere (Mac/PC), Final Cut Pro, iMovie (Mac)Premiere (Mac/PC), Final Cut Pro, iMovie (Mac)

7. Post Production So what’s it take to put together a good DV capture and editing system? A computer with a fast processor and lots of RAM A computer with a fast processor and lots of RAM 60 to 90 GB of fast hard disc storage 60 to 90 GB of fast hard disc storage A video capture card or native firewire A video capture card or native firewire A non-linear editing program A non-linear editing program Recording equipment (VTR/DVCR, CD-R or DVD drive) Recording equipment (VTR/DVCR, CD-R or DVD drive) And all of this for under $2500

8. Video Compression Why compression? bandwidth and playback limitations bandwidth and playback limitations Video compression/decompression requires a codec software/hardware technology that reduces the amount of information within individual video frames software/hardware technology that reduces the amount of information within individual video frames Factors that effect video compression bit depth - number of colors displayed bit depth - number of colors displayed frame size - number of pixels used to store each frame frame size - number of pixels used to store each frame frame rate - number of video frames captured/played per second frame rate - number of video frames captured/played per second

9. Video Compression 3 primary criteria to consider when selecting a codec Compression level Compression level Quality of compressed video Quality of compressed video Compression/Decompression speed Compression/Decompression speed It’s during the decompression process that codecs display their strengths and weaknesses Video compression tools Cleaner 5 Cleaner 5 QuickTime QuickTime

10. Video Compression Legacy codecs Cinepack (Web/CD-ROM) Cinepack (Web/CD-ROM) Photo JPEG (Web) Photo JPEG (Web) Apple Video (CD-ROM) Apple Video (CD-ROM) Animation (Web/CD-ROM) Animation (Web/CD-ROM) Graphics (Web/CD-ROM) Graphics (Web/CD-ROM) Modern codecs Sorenson Video (Web/CD-ROM) Sorenson Video (Web/CD-ROM) On2 VP3 (Web/CD-ROM) On2 VP3 (Web/CD-ROM) MPEG-2 (DVD-video) MPEG-2 (DVD-video) MPEG-4 (Web) MPEG-4 (Web) Real G2/RealVideo 8/9 (Web) Real G2/RealVideo 8/9 (Web)

11. Video Compression Legacy codecs Cinepack (Web/CD-ROM) Cinepack (Web/CD-ROM) Good for medium quality CD-ROM video Good for medium quality CD-ROM video Extremely low CPU requirements - works well on older computers Extremely low CPU requirements - works well on older computers Built into MS Video for Windows and QuickTime Built into MS Video for Windows and QuickTime Lower quality than many other codecs at the same data rates Lower quality than many other codecs at the same data rates Doesn’t produce good results at Web data rates (below 30KBps) Doesn’t produce good results at Web data rates (below 30KBps) Photo JPEG (Web)Photo JPEG (Web) Used for still images & editing and storage of high-quality video files Used for still images & editing and storage of high-quality video files Built into MS Video for Windows and QuickTime Built into MS Video for Windows and QuickTime Good choice for low-data rate slide show movies Good choice for low-data rate slide show movies Not well suited for CD-ROM or higher data rates Not well suited for CD-ROM or higher data rates Other codecs are better suited for Web-based video Other codecs are better suited for Web-based video

12. Video Compression Legacy codecs (cont.) Apple Video (CD-ROM)Apple Video (CD-ROM) Very fast codec but with low quality playback Very fast codec but with low quality playback Rapid compression makes it appropriate for testing edits Rapid compression makes it appropriate for testing edits Built into QuickTime Built into QuickTime Generally better suited for CD-ROM than for Web-based video Generally better suited for CD-ROM than for Web-based video Plays well on lower-end machines Plays well on lower-end machines

13. Video Compression Legacy codecs (cont.) Animation (Web/CD-ROM)Animation (Web/CD-ROM) Best suited for two-dimensional animation and computer generated (synthetic) video content Best suited for two-dimensional animation and computer generated (synthetic) video content Built into QuickTime Built into QuickTime As a lossless codec it doesn’t introduce any noise into the video signal As a lossless codec it doesn’t introduce any noise into the video signal Produces large files when quality set to 100% Produces large files when quality set to 100%

14. Video Compression Legacy codecs (cont.) Graphics (Web/CD-ROM)Graphics (Web/CD-ROM) Similar in function to the Animation codec but only generates 8-bit images (256 colors) Similar in function to the Animation codec but only generates 8-bit images (256 colors) Generally produces files about 1/2 the size of the Animation codec Generally produces files about 1/2 the size of the Animation codec Playback requires somewhat higher CPU requirements than Animation codec Playback requires somewhat higher CPU requirements than Animation codec Built into QuickTime Built into QuickTime

15. Video Compression Modern codecs Sorenson Video (Web/CD-ROM)Sorenson Video (Web/CD-ROM) Built into QuickTime Built into QuickTime Enables variable bit rate (VBR) encoding Enables variable bit rate (VBR) encoding Host of configurable features in the pro-version Host of configurable features in the pro-version Low data-rates make it superior for the Web Low data-rates make it superior for the Web CD-ROM playback requires 100 Mhz + machine CD-ROM playback requires 100 Mhz + machine Web playback requires Pentium or PowerMac Web playback requires Pentium or PowerMac

16. Video Compression Modern codecs (cont.) On2 VP3 (Web/CD-ROM)On2 VP3 (Web/CD-ROM) Recently developed open source codec Recently developed open source codec Built into QuickTime and soon to be integrated into RealPlayer Built into QuickTime and soon to be integrated into RealPlayer Enables clear 320x240 video that can be expanded to a full-screen 640x480 resolution Enables clear 320x240 video that can be expanded to a full-screen 640x480 resolution Low data-rates make it superior for both the Web and CD-ROM Low data-rates make it superior for both the Web and CD-ROM Low CPU demands on the playback computer Low CPU demands on the playback computer Outperforms the Sorenson codec Outperforms the Sorenson codec

17. Video Compression Modern codecs (cont.) MPEG-2 (DVD-video) MPEG-2 (DVD-video) Standard for broadcast-quality digitally encoded video Standard for broadcast-quality digitally encoded video Primarily used for DVDs Primarily used for DVDs Excellent quality at high data rates (300 - 1000 KBps) Excellent quality at high data rates (300 - 1000 KBps) Playback currently requires special hardware Playback currently requires special hardware Not appropriate for use over networks connections Not appropriate for use over networks connections

18. Video Compression Modern codecs (cont.) MPEG-4 (Web)MPEG-4 (Web) Currently under development for delivering interactive multimedia across networks Currently under development for delivering interactive multimedia across networks Based on the QuickTime file format and optimized for delivery of video at Internet data rates Based on the QuickTime file format and optimized for delivery of video at Internet data rates To be implemented in both MS NetShow and QuickTime 6 To be implemented in both MS NetShow and QuickTime 6

19. Video Compression Modern codecs (cont.) Real G2 (Web)Real G2 (Web) First modern video codec for the RealPlayer First modern video codec for the RealPlayer Creates a good looking image on high-end machines while playing adequately on low-end systems Creates a good looking image on high-end machines while playing adequately on low-end systems Can be used with or without special server software Can be used with or without special server software Video can be viewed with a free client application or plug-in Video can be viewed with a free client application or plug-in

20. Video Compression Modern codecs (cont.) RealVideo 8 (Web)RealVideo 8 (Web) Part of the RealMedia architecture designed to support live and on- demand audio and video over the Web Part of the RealMedia architecture designed to support live and on- demand audio and video over the Web Offers very good performance with lower data rates and motion intensive video Offers very good performance with lower data rates and motion intensive video Final version of RealMedia will support animations, MIDI, text, images, vector graphics and presentations Final version of RealMedia will support animations, MIDI, text, images, vector graphics and presentations

21. Video Compression Modern codecs (cont.) RealVideo 9 (Web)RealVideo 9 (Web) Just released today for Wintel machines Just released today for Wintel machines Provides 30% improvement over RealVideo 8 and 50% over RealVideo G2 Provides 30% improvement over RealVideo 8 and 50% over RealVideo G2 Same quality at 1/2 the bit rate of MPEG-4 Same quality at 1/2 the bit rate of MPEG-4 1/2 screen playback at dialup rates (56Kbps), VHS quality at broadband (160+ Kbps), and near DVD quality at LAN (500 Kbps) rates 1/2 screen playback at dialup rates (56Kbps), VHS quality at broadband (160+ Kbps), and near DVD quality at LAN (500 Kbps) rates

22. Output Options Many options - Tape, Web, CD or DVD Dump-to-tape is good for classroom viewingDump-to-tape is good for classroom viewing Web, CD and DVD require compressionWeb, CD and DVD require compression Web-based streaming and progressive downloadWeb-based streaming and progressive download Discreet’s Cleaner 5 (Mac/PC)Discreet’s Cleaner 5 (Mac/PC) QuickTime Pro (Mac/PC)QuickTime Pro (Mac/PC) Be sure and flatten Mac movies so they can play on a PCBe sure and flatten Mac movies so they can play on a PC Burning CDs (650 MB)Burning CDs (650 MB) Roxio’s Toast (Mac/PC)Roxio’s Toast (Mac/PC) Apple’s built-in Disc BurnerApple’s built-in Disc Burner DVD authoring (4.5 GB)DVD authoring (4.5 GB) Apple’s iDVD or DVD Studio ProApple’s iDVD or DVD Studio Pro Sonic Solutions DVDit (PC)Sonic Solutions DVDit (PC)

23. Resources on the Web Codec Central http://www.siggraph.org/education/materials/HyperGraph/video/codecs/Default.htm 2-Pop: The Digital Filmmaker's Resource Site http://www.2-pop.com Adobe Digital Video Tutorials http://www.adobe.com/motion/tips/main.html Digital Video Tutorial http://www.huntfor.com/photography/tutorials/digitvideo.htm Creating Video on the Macintosh http://www.apple.com/creative/video/workflow/ iMovie Support Page http://www.info.apple.com/usen/imovie/

24. Contact Information Jim Demmers 404-894-8056jim.demmers@gtri.gatech.edu